Interevaluator variability in the measurement of proximal articular set angle.

The proximal articular set angle (PASA) is used in the evaluation of hallux abducto valgus, as well as a criterial parameter for the selection or rejection of various hallux abducto valgus corrective procedures. The authors casually observed variability in the measurement of PASA in clinical situations, stimulating the development of the presented study to determine if, in fact, the measurement of PASA varies excessively from one physician to another. The results clearly indicate that the interevaluator measurement of PASA is excessive (p less than 0.001 in seven of eight x-ray series and p less than 0.01 in one of eight x-ray series). The authors discuss the clinical implications of the findings. Furthermore, the shortcomings of the study are discussed, specifically the inability to conclude about intraevaluator variability.